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Method for preparing branched polymer by conventional free radical polymerization

A branched polymer and free radical technology, applied in the field of branched polymer preparation, can solve problems such as poor polymer stability, unstable branched monomers, incompatibility, etc., and achieve mild reaction conditions and simple reaction system composition. , the effect of strong adaptability

Inactive Publication Date: 2014-02-05
JIANGSU POLYTECHNIC UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] (1) Yamada uses a polymerizable chain transfer agent to carry out free radical polymerization to synthesize branched polymers, but its shortcomings: there are serious defects in molecular design, and the branched monomer itself contains a chemical weak bond structure, so that the branch point is a chemical bond. Weak bonds, the existence of a large number of weak bonds on the polymer backbone makes the stability of the polymer poor
But its shortcoming: a large amount of mercaptans make the molecular weight of the polymer formed in the early stage of the reaction very low (about several thousand), and as the concentration of mercaptans decreases, the molecular weight of the polymer formed in the later stage of the reaction is very high or even cross-linked, so the molecular weight distribution is very low. Width (up to 105)
[0015] b. The molecular weight distribution of the obtained branched polymer is very wide, easy to cross-link in the later stage of the reaction, and the monomer conversion rate is low,
[0016] c. The use of branched monomers is very unstable and difficult to preserve. There are many by-products in the reaction product, and the applicability of the reaction monomer is narrow—it cannot be adapted to the vinyl acetate system

Method used

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  • Method for preparing branched polymer by conventional free radical polymerization
  • Method for preparing branched polymer by conventional free radical polymerization
  • Method for preparing branched polymer by conventional free radical polymerization

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0028] With reaction monomer (styrene, 104g, 1.0mol), branched monomer mercaptohexyl methacrylate (2.02g, 0.01mol) and initiator (AIBN, 0.82g, 5mmol) and solvent toluene (52g) join in In the reaction bottle, under the protection of inert gas, the reaction was carried out at 70° C. for 6 hours with stirring, and then at 100° C. for 8 hours to obtain a polymer with a styrene conversion rate of 90%. Polymer is analyzed by three-detection gel permeation chromatography, and the results are as follows: light scattering weight average molecular weight M w.MALLS =128500, M w.MALLS / M w.GPC =1.31, intrinsic viscosity η w = 38.2 mL / g, Mark-Houwink index α = 0.532, branching factor g' = 0.72, confirming that the obtained polymer has a branched structure.

example 2

[0030] With reaction monomer (methyl methacrylate, 100g, 1.0mol), branched monomer mercaptohexyl methacrylate (2.02g, 0.01mol) and initiator (AIBN, 0.82g, 5mmol) and solvent toluene (50g ) into a reaction flask, stirred under the protection of an inert gas, reacted at 70°C for 6 hours, and then reacted at 100°C for 8 hours to obtain a polymer, and the conversion rate of methyl methacrylate reached 99%. Polymer is analyzed by three-detection gel permeation chromatography, and the results are as follows: light scattering weight average molecular weight M w.MALLS =954600, M w.MALLS / M w.GPC =2.84, intrinsic viscosity η w = 91.5 mL / g, Mark-Houwink index α = 0.534, branching factor g' = 0.16, confirming that the obtained polymer has a branched structure.

example 3

[0032] With reaction monomer (vinyl acetate, 86g, 1.0mol), branched monomer mercaptohexyl methacrylate (2.02g, 0.01mol) and initiator (AIBN, 0.82g, 5mmol) and solvent toluene (43g) add Put it into a reaction flask, stir under the protection of an inert gas, react at 70°C for 6 hours, and then react at 100°C for 8 hours to obtain a polymer with a conversion rate of vinyl acetate of 92%. Polymer is analyzed by three-detection gel permeation chromatography, and the results are as follows: light scattering weight average molecular weight M w.MALLS =108400, M w.MALLS / M w.GPC =1.32, intrinsic viscosity η w = 43.2 mL / g, Mark-Houwink index α = 0.573, branching factor g' = 0.10, confirming that the obtained polymer has a branched structure.

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Abstract

The invention discloses a method for preparing a branched polymer by conventional free radical polymerization and relates to a method for preparing a branched polymer. The method is characterized in that the branched polymer is prepared through conventional free radical polymerization one-step method and by adopting the following step of: reacting 10-100 parts of alkene monomers, such as styrene, (methyl) acrylate or vinylacetate, and the like as a monomer, 0.1-10 parts of (methyl) acrylate monomer containing sulfydryl as a branched monomer and 0-100 parts of benzene or toluene as a solvent at 50-120 DEG C in the presence of a free radical polymerized initiator for 8-36 hours. The invention for preparing the branched polymer by sulfydryl chain transfer under the condition of conventional free radical polymerization has stable polymerization system, mild polymerization condition, simple and easy operation, high applicability of various alkene monomers and high monomer converting rate.

Description

technical field [0001] The invention relates to a preparation method of a branched polymer. A free radical polymerization initiator is mixed with a reaction monomer and a branched monomer, and a conventional free radical polymerization one-step method is used to obtain a polymer with a branched structure. Background technique [0002] In the past 20 years, branched polymers (Branched polymers) have been widely concerned in the polymer academic and industrial circles. Improving the transparency of thermoplastic elastomers has broad application prospects. The application prospects of branched polymers have attracted a large number of domestic and foreign experts and scholars, among which a lot of work has been done on the synthesis of branched polymers. At present, domestic and foreign scholars mainly focus on the preparation of vinyl branched polymers. Polymerization (as in methods 2-4 below). [0003] The synthetic methods of branched polymers mainly include: [0004] 1. ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F212/08C08F220/38C08F220/14C08F218/08
Inventor 蒋必彪黄文艳
Owner JIANGSU POLYTECHNIC UNIVERSITY